The U.S. Department of Energy Nuclear Energy University Program awarded five out of 51 grants nationwide to University of Wisconsin-Madison researchers in the Department of Engineering Physics.

In total, the DOE awarded $39 million in research grants aimed at developing cutting-edge nuclear energy technologies and training and educating the next generation of leaders in the U.S. nuclear industry.

With a $1,055,456 grant, Izabela Szlufarska, an associate professor of materials science and engineering and engineering physics, will study the effects of radiation on fission product transport in silicon carbide. Nuclear fission products are the atomic fragments left after a large atomic nucleus fissions. Silicon carbide is currently used to coat fuel particles in very-high-temperature reactor applications. One of the major problems with silicon carbide in this application is undesired diffusion of silver from the fuel core into the coolant. Understanding microstructure- and environment-dependent mechanisms that control silver diffusion through silicon carbide is needed in order to design a coating with superior retention capabilities. Dane Morgan, an associate professor of materials science and engineering and engineering physics, and Todd Allen, a professor of engineering physics, are collaborating on the project.

Wisconsin Distinguished Professor of Engineering Physics Michael Corradini was awarded $1,199,781 to study critical heat flux phenomena under high-pressure and low-mass flux conditions, in a heated rod bundle for modular reactor core designs. Modular reactors call for pressurized water reactors to be installed below ground level and to rely on passive safety systems that are simpler and less prone to malfunctions. Refueling will be needed only once every five years during the expected 60-year lifespan.

Critical heat flux describes the thermal limit of a phenomenon where a phase change occurs during heating (such as bubbles forming on a metal surface used to heat water), which suddenly decreases the efficiency of heat transfer, thus causing overheating of the heating surface. The critical heat flux phenomenon is one of the key physical phenomena that limit the allowable linear power for a nuclear reactor core design under steady-state operating conditions, and can be a limiting condition when the reactor coolant system temperature and/or pressure is affected by a change in the power output of the reactor. Mark Anderson, a senior scientist in engineering physics, and Oregon State University Associate Professor Qiao Wu are collaborating on the project.

Corradini was also awarded $1,199,988 to conduct safety analysis research on the next generation nuclear plant (NGNP). An NGNP would rely on high-temperature gas-cooled reactors that can provide high-temperature heat for industrial processes. The system uses helium rather than water to cool the nuclear core and transfer heat for energy conversion. Corradini’s research focuses on providing practical tools to analyze the reactor thermal hydraulics, system performance, and reactor gas-coolant helium thermal fluids behavior during transients, postulated accidents and safety evaluations. The reactor cavity cooling system is a key safety system, important to the NGNP passive safety concept. The air-cooling option for the design is in line with anticipated small modular reactors. The team’s work will support the expected final design and safety analysis of the cooling system for the NGNP.

The researchers will conduct scaled, air-cooled cooling system experiments coordinated with the larger-scale Nuclear Science and Technology facility experiments, as well as develop computational models describing key phenomena that occur during passive natural convection in the cooling system.

Professors Akira Tokuhiro of the University of Idaho and Yassin Hassan of Texas A&M University are collaborating on the project.

Todd Allen was awarded $1 million to develop advanced high-uranium-density fuels for light water reactors. Because highly enriched uranium may increase the danger of nuclear proliferation, researchers continue to improve low enriched uranium alloys with high uranium density. The challenge is to create a high-density fuel that can be manufactured and reprocessed.

Allen is investigating a single phase compound uranium silicide and a two-phase composite of uranium dioxide. The composites will be evaluated for irradiation stability, high temperature water corrosion resistance, thermal conductivity and mechanical properties, such as hardness and fracture toughness. In addition, Allen’s team will study the effect of ion irradiation on microstructure evolution, thermal and mechanical property changes.

Combined ion and neutron irradiation results generated with the help of Boise State University will improve the current understanding of irradiation stability and water corrosion resistance of high uranium density compounds, and will make a significant positive impact on the development of advanced nuclear fuels.

Professor Darryl Butt of Boise State University and Mitch Meyer of Idaho National Laboratory are collaborating on the project.

With $1.2 million in funding, Associate Professor Paul Wilson will lead a team in designing and developing the user experience for a next generation nuclear fuel cycle simulator (NGFCS).

With its recent roadmap for research, development and deployment, the DOE Office of Nuclear Energy seeks to ensure that nuclear energy continues to be a competitive energy option for decades to come. Development of sustainable fuel cycles is a primary challenge. Decisions for individual nuclear energy technologies must be informed by the technical, political and socioeconomic impacts of those technologies on the whole nuclear energy system. The Fuel Cycle Research & Development Program is creating a next-generation fuel cycle simulator with sufficient modularity to accommodate a wide variety of audiences, use cases and developer needs.

The NGFCS is expected to be a useful evaluation tool for a variety of audiences. Non-technical audiences will interact with the NGFCS in a way that allows them to express critical high-level decisions and understand the outcomes of those decisions in a set of key metrics. Expert audiences may be interested in a quantitative technology assessment to help motivate design improvements. Developers of the NGFCS will need to visualize their results to ensure consistency and correctness. At the same time, it is important that the NGFCS allow experts to introduce new modules to capture specific physical models or market behavior, but rely on a common infrastructure that facilitates direct comparisons of results.

In addition to ensuring an adequate user environment for developers, including input generation and detailed quantitative output visualization, Wilson’s team will pay particular attention to the policy- and decision-maker audience that may be interested in trends and trade-offs in a more qualitative manner. An interdisciplinary team will combine research in social science, computer science and nuclear engineering to support an innovative interface for nuclear fuel cycle systems analysis. UW-Madison Associate Professor of Life Sciences Communication Dominique Brossard, Valerio Pascucci of the University of Utah, Erich Schneider of the University of Texas-Austin, and Robert Hiromoto of the University of Idaho are collaborating on the project.